Turtle

Turtles are animals with hard shells.

The shell is part of their body. It is made from their ribs. The top part is a dome. The bottom part is flat.

The shell is covered in scales. These scales are like your hair. Turtles live in many places. Some live in the ocean. Some live on land.

They breathe air just like us. Some turtles are very big. Others are very small. Turtles are amazing animals.

Turtles are amazing reptiles with hard shells.

The shell is part of their body. It grows from their ribs. The top part is called the carapace. The flat bottom part is the plastron.

The shell is covered in scales. These are made of keratin. Keratin is the same stuff in your hair and nails.

Turtles live in many places. Some live on land. These are often called tortoises. Others live in water. Some live in ponds. Others live in the big ocean.

Sea turtles are the only reptiles that swim long distances to lay eggs.

Turtles are cold-blooded. This means their body temperature changes with the world around them. They eat many things. Most eat plants or small animals.

Some turtles are very large. The leatherback sea turtle can weigh over 600 kilograms. Other turtles are very tiny. The smallest turtle is only 8 centimeters long.

Many turtles are now in danger. Their homes are being lost. This makes it hard for them to survive.

Turtles are fascinating reptiles known for their protective shells.

There are about 360 different species of turtles living today. Some live on land, like tortoises, while others live in freshwater or the ocean.

All turtles breathe air and do not lay eggs underwater. They are ectotherms, which means they are cold-blooded. This means their body temperature changes with the world around them. Most turtles are opportunistic omnivores that eat plants and small animals.

A turtle's shell is a unique part of its body.

The top part is a dome called the carapace. The flat belly part is called the plastron. The carapace actually grows from the ribs. As a turtle grows, its ribs grow sideways to form the shell. The outside of the shell is covered in scales called scutes. These scutes are made of keratin. This is the same material found in your hair and fingernails.

People have studied and named turtles for a very long time.

In 1788, a German naturalist named August Batsch gave them the official name Testudines. This name comes from a Latin word for tortoise. Other names like Chelonii were used in the past too. They come from an ancient Greek word. In different parts of the world, people use different names. In Britain, people use "turtle" for sea turtles. In Australia, they often call non-marine turtles tortoises.

Turtles come in many different sizes.

The leatherback sea turtle is the largest living species. It can grow over 2 meters long and weigh over 600 kilograms. The smallest turtle is the Chersobius signatus from South Africa. It is only about 8 centimeters long and weighs very little. Some turtles are also very fast swimmers. Sea turtles use their front limbs like wings to move through the water. This helps them swim much faster than freshwater turtles.

Many turtles are in trouble today because their habitats are being destroyed.

Some are also hunted for their meat or their shells. Sea turtles can even be caught by accident in fishing nets. Because of these hard jobs, many species are now threatened with extinction. We can learn a lot by watching how they live. For example, some turtles have seven types of color-detecting cells in their eyes. This helps them see the world in amazing detail.

Turtles belong to the order Testudines. They are a unique group of reptiles defined by a specialized shell. This shell provides both protection and shelter from the environment. There are 360 living and recently extinct species of turtles. These include land-dwelling tortoises and freshwater terrapins.

Modern turtles are divided into two major groups. These are the Pleurodira, or side-necked turtles, and the Cryptodira, or hidden-necked turtles. They are distinguished by how they retract their heads into their shells.

The turtle shell is a complex anatomical structure.

It consists of 50 to 60 bones. The upper, domed part is called the carapace. The flatter underside is the plastron, or belly-plate. These parts are connected by lateral extensions of the plastron. The carapace is fused with the vertebrae and the ribs. During development, the ribs grow sideways into a carapacial ridge. This ridge supports the carapace as it forms. Proteins called fibroblast growth factors, such as FGF10, signal this growth. The outer surface is covered in keratin scutes. Keratin is the same material found in hair and fingernails.

Different environments have shaped the variety of turtle shells. Land-dwelling turtles often have dome-shaped shells. This shape helps them resist being crushed by large animals. Aquatic turtles typically have flatter, smoother shells. This shape allows them to cut through water more easily. Sea turtles have streamlined shells to reduce drag in the open ocean. Some species have even evolved spikes or lumps for camouflage or protection.

Some turtles, like box turtles, have shells where the bones are fully fused. Others, known as softshell turtles, have rubbery edges because they lack certain bones. The leatherback sea turtle is unique because it has very little bone in its shell. Instead, it uses thick connective tissue and leathery skin.

Turtles have a long history of scientific study and naming. The name Testudines was coined by the German naturalist August Batsch in 1788. This name is based on the Latin word for tortoise. The order has also been called Chelonii and Chelonia. These names come from the Ancient Greek word for tortoise. The term chelonian is often used as a formal name for members of the group.

Naming conventions can vary by region. In Britain, "turtle" usually refers to sea turtles. In Australia, the term "turtle" is now often used for the entire group. In North America, the name may refer to the entire order.

Turtles exhibit an incredible range of sizes.

The leatherback turtle is the largest living species. It can reach over 2 meters in length and weigh over 600 kilograms. The largest known prehistoric turtle was Archelon ischyros. It lived during the Late Cretaceous and was up to 4 meters long. It is estimated to have weighed over 2,000 kilograms. Conversely, the smallest living turtle is Chersobius signatus from South Africa. It measures no more than 8 centimeters and weighs very little.

Locomotion and feeding habits vary greatly among species.

Turtles are ectotherms, meaning their internal temperature follows the environment. Most are opportunistic omnivores. They eat plants and animals with limited movement. Some species have very powerful bites. The durophagous Mesoclemmys nasuta has a bite force of 1,100 newtons. Because they lack teeth, they use keratin beaks to eat. Sea turtles are specialized swimmers. They use their front limbs like wings to create thrust. This makes them much faster and more efficient than freshwater turtles.

Despite their resilience, many turtles face significant threats.

Habitat destruction is a major problem for many species. Some turtles are hunted for their meat, shells, or for traditional medicine. Sea turtles are also frequently killed as bycatch in fishing nets. These pressures have caused many species to become extinct or threatened. Protecting their habitats is essential for their survival. Understanding their unique biology helps us better protect these ancient reptiles.